Snow Report April 15th
Winter Returns to the Off Piste
Snow off and on from 16 through 19 April in much of the Northern French Alps.
In the Mountain Echo Last week I said that when a sunny facing slope has been in the sun for a long time, it is unstable. When the snowpack on that same slope has frozen, it is very stable. So it’s easier to predict the snow stability on slopes that have been subjected to melting and freezing.
I then went on to say that we need to still be careful of cold dry snow avalanches at this time of year and explained why North facing slopes can still be dangerous/unstable after a snowstorm: because they have not been subjected to melting and freezing just after a snowstorm, the instability can linger for a while.
After the massive avalanche (on a West facing slope) this past Monday 13 April in Val d’Isère, I believe I should have said North facing slopes OR any slopes that have NOT been subjected to melting and freezing, such as very high East and West facing slopes that have had recent snowfall and/or wind-loading.
The slope that took Chippie, Scandy Jo and buried Mark (the publisher of the Echo), is West facing, was triggered by the victims mid-morning and released at approximately 3400 m. It was a day or so after a lot of snow fell in the area with winds coming out of the East. The crown ran 400 m long and was 30-50 cm deep.
Lucky our friend Mark was dug out alive (for photos see the post on my blog for the 13th of April.)
Which get me to a reflection rather than a Tip of the week:
As of this writing, 16 April, there have been a number of avalanche accidents in the last 10 days or so. Some tragic all potentially deadly and all these avalanches have been dry slab avalanches i.e. not snow that has ever been fully melted.
Furthermore, I can think of a number of people who have been taken and severally injured or killed off-piste at this time of year in similar conditions: after spring snowfalls and on slopes where the snow was still wintry, fairly light and dry.
Why? I’m not sure. But it is going to be snowing off and on from 16 -19 April in much of the Northern French Alps. So best to continue to stick to the basic points of risk management in order to have fun and be safe out there in the off piste:
A) Think about your choice of slope and which direction it is facing: N,S,E,W (be aware of recent avalanche activity and where it has occurred)
B) Keep good distances between each group member on or below slopes steep enough to avalanche so you minimize stress on the slope and you only expose one person at a time to any risk (like cliffs, trees, rocks or narrow valley bottoms bellow)
C) Stop/regroup at islands of safety (places that are not exposed to avalanches above and/or not exposed to danger below).
Have Fun, Be Safe!
Henry and the HAT Team
See Henry's Avalanche Talk for events this week!
